Systems have been proposed for cutting and trimming various types of products, such as food products, through the use of highly focused and highly pressurized jets of liquid (referred to as "liquid-jet cutting"). During implementation, the cutting device is located upon a robotic arm proximate a conveyance system which brings the product to be cut in close proximity to the cutting device. Thereafter, the cutting device directs a high pressure jet of liquid onto the product to cut the product. Past cutting systems utilize valves which open and close to turn the liquid-jet on and off. However, such systems were undesirable since the valves operate slowly and require an unduly long time period to open and close. The slow operating speed was at least partially attributed to the fact that the valve was a "flow through" type of valve, wherein the valve sealed an opening therethrough against the high pressure liquid-jet when closed. Such valves are necessarily large and heavy in order to halt the liquid-jet and withstand the high pressures used in liquid-jets. The size and mass associated with such valves limit their reaction speed. Additionally, the mass of the valve reduces the cutting capacity of the robotic arm which supports the cutting device and moves same during operation.
To overcome the foregoing disadvantages of the flow-through type of valve, a "deflector" type of valve has been proposed. The conventional deflector valve includes a flat deflector bar located proximate the discharge end of the nozzle of the liquid-jet cutting device. The deflector bar is rectangular in shape and is supportably mounted at an inner end to the drive shaft of a pneumatic rotary cylinder. The pneumatic rotary cylinder is mounted to the system's frame and oriented with its rotational axis aligned parallel to the path of the liquid-jet stream. The rotary cylinder drivably pivots the bar-shaped deflector along an arcuate path within a plane perpendicular to the path of the jet, such that an outermost end of the bar moves between engaged and disengaged positions. When the bar-shaped deflector is in an engaged position, its outer end is located immediately below the nozzle to block the path of the liquid-jet sprayed therefrom. When in a disengaged position, the outer end of the bar-shaped deflector is located remote from and does not interfere with the liquid-jet path.
However, the conventional deflection method has met with limited success. In this conventional system, the nozzle of the liquid-jet and the deflector bar are maintained a fixed vertical distance from one another when engaged and disengaged. The nozzle must be located sufficiently close to the product to achieve the desired cutting effect. To interrupt a cutting operation, the deflection bar is rotated to rest between the nozzle and the product. However, as the nozzle must be located close to the product, so must the deflector plate be located close to the nozzle to afford the least possible operating range between the nozzle and the product. Otherwise, the cutting device becomes inoperative since, as the distance between the nozzle and deflector bar increases, the distance between the nozzle and product must necessarily increase, which reduces the cutting efficiency. Due to these space limitations, the deflection plate must be rotated to a position immediately adjacent the nozzle to deflect the water, and thus the liquid-jet wears substantially upon the deflection bar. The conventional system attempts to minimize this wearing factor by providing an insert at the outer end of the deflection bar formed of an extremely hard material to receive the direct stream of the liquid-jet. However, the insert still wears, thereby affording a short life for the deflection mechanism.
In addition, the conventional deflector mechanism limits a minimum operating distance between the nozzle and the product since the deflector bar must be afforded space to rotate between the nozzle and the product. This minimum operating distance is insufficient to allow optimal cutting and accuracy.
Further, the conventional deflector mechanism produces a tremendous volume of liquid spray emitted in all directions from the point of contact with the product or deflector bar, thereby reducing visibility in the region of the nozzle. Moreover, the conventional deflector mechanism repetitively directs the liquid-jet onto the deflector bar at a single point. Hence, the bar wears quickly at the point of contact and must be changed quite often.
A need remains within the industry for an improved deflector mechanism. The present invention meets this need and overcomes the disadvantages of the above-noted systems.